Glen tress black

Firstly dont be put off by the "black". It is technically no harder than the red, it is just longer. A lot longer. In total you climb about 3000 feet - the same as a Munro. I cant remember how long it is but i think it is about 17-19 miles.
If you can do the glentress red then you can do the black - in fact there is nothing particularly technical about it. There's nothing that steep and nothing other than just a nice, albeit stony path in the hills. Towards the very end we miss out any technical sections. I would rate the black here about the same as carron valley or wolftrax red. In fact wolftrax red is actually harder. We will take our time around this, so all you need to do is a bit of training to make sure you can do the distance.

make sure you bring spare inner tubes - the surface is a little uneven so punctures are fairly common.